A tropical travel hotspot is facing an outbreak of a deadly mosquito-borne virus as cases spread in the Americas.
The CDC issued a Level 2 travel advisory for Costa Rica, urging US citizens to ‘practice enhanced precautions’ as chikungunya plagues the Guanacaste Province.
The incurable virus is spread through mosquito bites, which causes a life-threatening high fever, excruciating joint and muscle pain, and a rash.
Costa Rica's health ministry declared an active outbreak in the popular beach town Playa Langosta on July 1.
The US Embassy in the country alerted travelers to the outbreak last week, warning there was now local transmission of the virus, meaning it is present in the mosquito population and not just arriving in the country via people who have been infected elsewhere.
Out of 45 suspected cases, officials confirmed four were from the virus and 17 were classified as 'probable.'
The ministry said the the outbreak has impacted both Costa Rican nationals and foreigners.
So far, the vacation destination reported 16 confirmed cases of chikungunya virus this year, including during this active outbreak.
The CDC has issued a travel advisory for the area of Langosta Beach in Costa Rica, following an active outbreak of the chikungunya virus
A worker sprays insecticide at a residential community in Foshan, Guangdong Province of China, as it battled a record chikungunya outbreak last year
Costa Rica welcomes about 966,000 travelers from the US per year, according to the country's tourism institute.
And Playa Langosta is a widely visited beach community located on the northern Pacific coast in the Guanacaste Province.
The Pan American Health Organization (PAHO) first issued an epidemiological alert in February, following a rise of chikungunya virus cases in several countries in the Americas since late 2025 to early 2026.
The alert also spotlighted the recurrence of local transmission in areas that have not reported a virus case in several years.
'Chikungunya spread across the Americas in 2013, and after years of low transmission, we are now observing a resurgence, particularly in the Intertropical Zone where Aedes aegypti is present,' said Sylvain Aldighieri, director of communicable diseases prevention, control, and elimination at PAHO.
'The purpose of this alert is to ensure that health workers and governments are prepared for potential outbreaks and can plan public information campaigns.'
While the CDC did not specify what precautions travelers should take, a Level 2 warning typically requires using EPA-registered insect repellent, wearing long-sleeved shirts and long pants and ensuring hotel rooms or home rentals are fully sealed with screens or air conditioning.
The virus can be prevented with a vaccine and the CDC recommends all travelers get vaccinated before visiting areas experiencing a surge in cases.
As of February 28, the latest data available from the ECDC, there have been 32,758 chikungunya cases and nine associated deaths this year across at least 18 countries.
The outbreak is occurring in the Playa Langosta area, a widely visited beach community located on the northern Pacific coast in the Guanacaste Province
The chikungunya virus is transmitted to humans through bites from Aedes aegypti and Aedes albopictus mosquitoes infected with it
The fatal virus has already made it to the US. In September 2025, New York health officials reported that a 60-year-old woman from Hempstead, Long Island, was diagnosed with a suspected case the previous month.
Having not traveled off the island, lab tests have since confirmed she contracted the virus locally, marking the first locally acquired case ever recorded in New York City.
Three additional people in New York tested positive for chikungunya in 2025 after returning from countries where the virus is known to circulate, according to the city's Department of Health.
A massive outbreak of the virus plagued China in July 2025, with over 3,000 confirmed cases in the first two weeks and more than 10,000 by late August.
Guangdong Province implemented aggressive COVID-era precautions, including eliminating stagnant water, releasing larvae-eating fish, door-to-door inspections, mandatory patient isolation and strict surveillance to curb the spread.
The chikungunya virus is transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes infected with it. Symptoms generally appear three to seven days after being bitten.
The infection first appears as a severe flu with a high fever and excruciating joint pain, typically in the hands, feet and knees. A rash, headache, and severe muscle aches quickly follow.
While most people start to feel better after a week or two, the joint pain can be persistent.
The above compares chikungunya symptoms to those from Zika virus and Dengue, which are both also spread by mosquitoes
For many, it lingers, causing ongoing stiffness, swelling and arthritis-like pain that can last for months or even years.
Officials warn pregnant women to reconsider their travel plans, especially if they are close to delivering. Mothers who become infected around the time of delivery can pass the virus to their baby before or during birth.
The CDC said: ‘Newborns infected in this way or by a mosquito bite are at risk for severe illness, including poor long-term outcomes,’ including cognitive deficits and developmental delays.
There is no specific treatment for chikungunya, but the death rate is generally low, around one in 1,000 symptomatic cases.
However, the risk of death is far higher, up to 15 percent, among people with pre-existing conditions such as diabetes, kidney and heart disease.
Chikungunya deaths are often more directly caused by complications from kidney and brain failure rather than the virus itself.